Threaded cam axle assembly for a compound archery bow

ABSTRACT

A tensioned cam assembly for a compound archery bow is disclosed. In one embodiment, the tensioned cam assembly includes a cam axle, pair of externally threaded set screws, and a pair of nuts. The cam axles has a first threaded end and a second threaded end opposite the first threaded end. Each nut includes a threaded bore extending therethrough in which the first or second threaded end of the cam axle is removably receivable. Each nut also includes a threaded aperture in which one set screw of the pair of set screws is removably receivable to selectively retain said nut in a desired position on said cam axle.

A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the reproduction of the patent document or the patent disclosure, as it appears in the U.S. Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application No. 62/754,464 entitled “THREADED CAM AXLE ASSEMBLY FOR A COMPOUND ARCHERY BOW” filed on Nov. 1, 2018.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

REFERENCE TO SEQUENCE LISTING OR COMPUTER PROGRAM LISTING APPENDIX

Not Applicable

BACKGROUND OF THE INVENTION

The present disclosure relates generally to the field of archery. More specifically, the present invention relates to a cam axle assembly for a compound archery bow.

In compound archery bows, the cams, bearings, and spacers of the cam system are connected to the bow limb(s) by a smooth axle that is typically retained on the limbs by a device such as a C-clip or an E-clip. Traditional cam axles and cam axle retention mechanisms permit undesirable lateral movement of the cams during operation of the bow, which reduces the accuracy of the bow. Accordingly, what is needed are improvements in compound archery bows and their axle assemblies.

BRIEF SUMMARY OF THE INVENTION

Aspects of the present invention provided a tensioned cam assembly for a compound archery bow. In one embodiment, the tensioned cam assembly includes a cam axle, pair of externally threaded set screws, and a pair of nuts. The cam axles has a first threaded end and a second threaded end opposite the first threaded end. Each nut includes a threaded bore extending therethrough in which the first or second threaded end of the cam axle is removably receivable. Each nut also includes a threaded aperture in which one set screw of the pair of set screws is removably receivable to selectively retain said nut in a desired position on said cam axle.

When installed on a compound archery bow in place of a traditional cam axle system, the tensioned or threaded cam axle assembly disclosed herein allows a user to selectably tighten the cam system in the limbs of the bow to a desired torque and minimize the space between components of the cam system connected to the limb such as the cam, bearings, and spacers, by simply tightening each nut onto one of the opposing threaded ends of the cam axle extending outside of the bow limbs. This allows the user to control the amount of friction in the cam system and eliminate undesirable lateral movement (i.e., wobble) of the cams during bow operation, thereby improving the accuracy of the bow. Once a desired amount of torque, friction, and/or space between components is reached, the user may lock the assembly in place on the bow limbs by threading a set screw into the threaded aperture of each nut, and tightening each set screw until each respective nut is prevented from backing off either end of the threaded cam axle and tightening in on the cam system.

In one aspect, the cam axle assembly for an archery bow includes a cam axle and the nut. The cam axle has a threaded end. The cam axle is configured to insert the repair of limb ends and a cam of the archery bow. The nut is configured to threadingly engage the threaded end of the cam axle to secure the cam axle to the pair of limb ends.

In another aspect, and archery bow includes a riser, a plurality of limbs, a pair of cam axle assemblies, a cam system, and a bowstring. The plurality of limbs extend generally rearward from the riser when the archery bow is assembled and in an upright position. The cam system is mounted on the cam axle assembly and includes at least one cam. The bowstring is supported by the cam of the cam system when installed on the archery bow. Each cam axle assembly of the pair of cam axle assemblies includes a cam axle, and a nut. The cam axle has a threaded end. The cam axles configured to insert through a pair of limb ends of the plurality of limbs of the archery bow. The nut is configured to threadingly engage the threaded end of the cam axle to secure the cam axle to the pair of limb ends.

Numerous other objects, advantages and features of the present disclosure will be readily apparent to those of skill in the art upon a review of the following drawings and description of a preferred embodiment.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a front isometric partially exploded perspective view of a threaded cam axle assembly for a compound bow showing the cam axle assembly positioned in a cam for an archery bow according to one embodiment of the invention.

FIG. 2 is a rear isometric partially exploded perspective view of the cam axle assembly shown in FIG. 1.

FIG. 3 is an elevated perspective view of the nut shown in FIG. 1.

FIG. 4 is a reverse elevated perspective view of the nut shown in FIG. 3.

FIG. 5 is an isometric view of a threaded cam axle assembly according to another embodiment of the invention.

FIG. 6 is an exploded isometric view of the cam axle assembly of FIG. 5.

FIG. 7 is a side perspective view of an archery bow including a tensioned cam system.

FIG. 8 is a top perspective view of the archery bow of FIG. 7 including the tensioned cam system.

Reference will now be made in detail to optional embodiments of the invention, examples of which are illustrated in accompanying drawings. Whenever possible, the same reference numbers are used in the drawing and in the description referring to the same or like parts.

DETAILED DESCRIPTION OF THE INVENTION

While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention and do not delimit the scope of the invention.

To facilitate the understanding of the embodiments described herein, a number of terms are defined below. The terms defined herein have meanings as commonly understood by a person of ordinary skill in the areas relevant to the present invention. Terms such as “a,” “an,” and “the” are not intended to refer to only a singular entity, but rather include the general class of which a specific example may be used for illustration. The terminology herein is used to describe specific embodiments of the invention, but their usage does not delimit the invention, except as set forth in the claims.

As described herein, an upright position is considered to be the position of apparatus components while in proper operation or in a natural resting position as described herein. As used herein, the upright position of a modern compound archery bow is when held by a user in a vertical orientation ready to draw and/or release (see FIG. 7). As used herein, archery bow refers to modern compound single limb or split limb bows or a compound crossbow. The upright position of a crossbow as described herein is when held by a user generally vertically (i.e., sideways) such that the limbs extend generally vertically. Forward is generally the direction in which a projectile is propelled from the archery bow when shot, and rearward is generally toward a user shooting the archery bow. Vertical, horizontal, above, below, side, top, bottom and other orientation terms are described with respect to this upright position during operation unless otherwise specified. The term “when” is used to specify orientation for relative positions of components, not as a temporal limitation of the claims or apparatus described and claimed herein unless otherwise specified. The terms “above”, “below”, “over”, and “under” mean “having an elevation or vertical height greater or lesser than” and are not intended to imply that one object or component is directly over or under another object or component.

The phrase “in one embodiment,” as used herein does not necessarily refer to the same embodiment, although it may. Conditional language used herein, such as, among others, “can,” “might,” “may,” “e.g.,” and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or states. Thus, such conditional language is not generally intended to imply that features, elements and/or states are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without operator input or prompting, whether these features, elements and/or states are included or are to be performed in any particular embodiment.

Referring to FIGS. 1-8, a cam axle assembly 10 foreign archery bow 100 is shown. The cam axle assembly 10 has a cam axle 20 and a nut 30. The cam axle 20 has a threaded end 22. The cam axle 20 is configured to insert through a pair of limb ends 103 and a cam 50 of the archery bow 100. The nut 30 is configured to threateningly engage the threaded end 22 of the cam axle 20 to secure the cam axle 22 the pair of limb ends 103. In one embodiment, a second end 24 of the cam axle 20 opposite the first end 22 of the cam axle 20 is larger than the first and 22 of the cam axle 20 such that the second end 24 will not fit through the limb end 103 (i.e., through a hole in the limb and 103). In another embodiment, the second end 24 of the cam axle 20 is also threaded. The cam axle assembly 10 further includes a second nut 30 configured to threateningly engage the threaded second end 24 of the cam axle 20 to secure the cam axle 22 the pair of limb ends 130. In one embodiment, the cam axle assembly 10 further includes the cam 50, and the cam 50 has a bearing assembly therein configured to receive the cam axle 20 such that the cam axle 20 supports the bearing and the cam 50 when the cam axle assembly 10 is installed on the archery bow 100.

Referring especially to FIGS. 1-4, in one embodiment, the nut 30 includes a threaded aperture 39 configured to receive a set screw 40. The set screw 40 is configured to prevent rotation of the nut 30 relative to the cam axle 20 when the cam axle assembly 10 is installed on the archery bow 100. In one embodiment, the cam axle simply 10 further includes the set screw 40. In one embodiment, the threaded aperture 39 is perpendicular to an axis 31 along which the axle 20 extends when the cam axle assembly 10 is installed on the archery bow 100. In one embodiment, the nut 30 has an outer surface 3 32 and an inner surface or limb surface 34. The inner surface 34 of the nut 30 is configured to contact the limb and 1 of 3 when the cam axle assembly 10 is installed on the archery bow 100. The nut 30 has an outer diameter at the inner surface 34 that is greater than the outer diameter of the nut 30 at the outer end surface 32. The outer diameters are measured perpendicular to the axis 31 of the cam axle 20 when the cam axle assembly 10 is installed on the limb end 103 of the archery bow 100. The outer diameter of the limb end surface 34 is larger and smooth to prevent marring of the limb and 103 when the nut 30 is tighten down on the limb end 103.

Referring especially to FIGS. 5 and 6, in one embodiment, the nut 30 does not include threaded aperture 39. Instead, the cam axle assembly 10 includes the set screw 40. The set screw is configured to threateningly engage the nut 30 and prevent rotation of the nut 30 about the cam axle 20 when the cam axle assembly 10 is installed on the archery bow 100. A longitudinal axis of the set screw 40 aligns with the axis 31 of the cam axle 20 when the cam axle assembly 10 is installed on the archery bow 100. The set screw 40 contacts the end of the cam axle 20 to jam the nut 30 and prevent rotation of the nut 30 about the cam axle 20 when the cam axle assembly 10 is installed on the archery bow 100.

Referring especially to FIGS. 7 and 8, in one embodiment, and archery bow 100 includes a riser 105, a plurality of limbs 107 a pair of cam axle assemblies 10, a cam system (e.g., a pair of matched cams 50 installed at opposing ends of the riser 105 via the limbs 107), and a bowstring 130. The plurality of limbs 107 extend generally rearward from the riser 105 when the archery bow 100 is assembled and in an upright position. The bowstring 130 is supported by the cam 50 of the cam system when the bowstring is installed on the archery bow 100. In one embodiment, the pair of limb ends 103 are limb ends of separate limbs 107. It is also contemplated within the scope of the claims that the limb ends 103 supporting a single cam axle assembly 10 may be two ends of a single limb (i.e., the limb 107 splits at the end 103 to provide a double shear arrangement for the cam axle assembly 10). In one embodiment, the archery bow 100 further includes a bow site 150 configured to mount the riser 105 when the archery bow 100 is assembled.

Embodiments of a threaded cam axle assembly 10 for a compound bow 100 are shown in FIGS. 1-8. In one embodiment, a threaded cam axle assembly 10 for a compound bow 100 includes an axle 20, first and second nuts 30, and first and second set screws 40 (i.e., one set screw 40 for each nut 30). The axle 20 includes a first threaded end 22 and a second threaded end 24 opposite the first threaded end 22. Each set screw 40 includes a threaded circumference 42 and a head 44. In one embodiment, each set screw can be a grub screw with a hex socket head 44 (as best shown in FIGS. 5-6). Each nut 30 includes a top surface 32, a bottom surface 34, a circumferential side 36, and a threaded bore along an axis 31 in which first or second threaded end 22, 24 of axle 20 is receivable. The threaded bore extends from the top surface 32 to the bottom surface 34 of the nut 30. The circumferential side 36 includes a plurality of flats 38 to facilitate tightening and loosening of the nut 30 on either threaded end 22, 24 of axle 20 with an open- or box-end wrench. In one embodiment, the nut 30 can further include a threaded aperture 39 (see FIGS. 3 and 4) in which the set screw 40 is receivable. The threaded aperture 39 is defined through circumferential side 36 such that the bore of the threaded aperture 39 perpendicularly intersects axle axis or bore 31. In another embodiment, the nut 30 can be a self-locking hex nut 30 (as shown in FIGS. 5-6) that omits separate threaded aperture 39.

Referring now to FIGS. 1-4, in one embodiment, once the first or second threaded end 22, 24 of cam axle 20 is received in the axle bore 71 of nut 30, set screw 40 is receivable in threaded aperture 39 of nut 30 to retain nut 30 in a given position on threaded end 22, 24 of cam axle 20 and thereby prevent nut 30 from backing off of the threaded end 22, 24 of cam axle 20 and removing tension from the cam axle assembly 10 located between the limb ends 103.

Referring now to FIGS. 5-6, in one embodiment, once the first or second threaded end 22, 24 of cam axle 20 is received in the axle bore 71 of nut 30, set screw 40 is receivable in the opposite end of the axle bore 71 of the nut 30 to retain nut 30 in a given location on threaded end 22, 24 of cam axle 20 and thereby prevent nut 30 from backing off of the threaded end 22, 24 of cam axle 20 and removing tension from the cam axle assembly 10 located between the limb ends 103.

The threaded cam axle assembly 10 can be installed on a compound archery bow 100 in the same way as a standard smooth cam axle. With the threaded cam axle assembly 10 installed on a compound archery bow in place of a standard cam axle, a user can modulate the torque, friction, and space between components of the cam system by tightening or loosening the nuts 30 on the first and/or second threaded ends 22, 24 of the axle 20. Once a desired amount of torque, friction, and/or space between components is reached, the user may lock the assembly 10 in place on the bow limbs 103 by threading set screw 40 into the nut 30 via either (i) the threaded apertures 39 in each nut 30 as shown in FIGS. 1-4, or (ii) the opposite end of the axle bore 71 of the nut as shown in FIGS. 5-6, and tightening each set screw 40 until each respective nut 30 is prevented from backing off either end 22, 24 of the threaded cam axle 20. This arrangement prevents the assembly 10 from changing friction or tension on the cam 50 while permitting the cam 50 through which the cam axle 20 extends to rotate and function as designed.

This written description uses examples to disclose the invention and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

It will be understood that the particular embodiments described herein are shown by way of illustration and not as limitations of the invention. The principal features of this invention may be employed in various embodiments without departing from the scope of the invention. Those of ordinary skill in the art will recognize numerous equivalents to the specific procedures described herein. Such equivalents are considered to be within the scope of this invention and are covered by the claims.

All of the compositions and/or methods disclosed and claimed herein may be made and/or executed without undue experimentation in light of the present disclosure. While the compositions and methods of this invention have been described in terms of the embodiments included herein, it will be apparent to those of ordinary skill in the art that variations may be applied to the compositions and/or methods and in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit, and scope of the invention. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope, and concept of the invention as defined by the appended claims.

Thus, although there have been described particular embodiments of the present invention of a new and useful THREADED CAM AXLE ASSEMBLY FOR A COMPOUND ARCHERY BOW it is not intended that such references be construed as limitations upon the scope of this invention except as set forth in the following claims. 

What is claimed is:
 1. A cam axle assembly for an archery bow, said cam axle assembly comprising: a cam axle having a threaded end, said cam axle configured to insert through a pair of limb ends and a cam of the archery bow; and a nut configured to threadingly engage the threaded end of the cam axle to secure the cam axle to the pair of limb ends.
 2. The cam axle assembly of claim 1, wherein: the threaded end is a first threaded end of the cam axle; the nut is a first nut; the cam axle has a second end opposite the first end of the cam axle; the second end of the cam axle is threaded; and the cam axle assembly further comprises a second nut configured to threadingly engage the threaded second end of the cam axle to secure the cam axle to the pair of limb ends.
 3. The cam axle assembly of claim 1, wherein: the cam axle assembly further comprises the cam, and the cam has a bearing assembly therein configured to receive the cam axle such that the cam axle supports the bearing and the cam.
 4. The cam axle assembly of claim 1, wherein: the nut comprises a threaded aperture configured to receive a set screw, said set screw configured to prevent rotation of the nut relative to the cam axle when the cam axle assembly is installed on the archery bow; and the cam axle assembly further comprises the set screw.
 5. The cam axle assembly of claim 1, wherein: the nut comprises a threaded aperture configured to receive a set screw, said set screw configured to prevent rotation of the nut relative to the cam axle when the cam axle assembly is installed on the archery bow; the threaded aperture is perpendicular to an axis along which the axle extends when the cam axle assembly is installed on the archery bow; and the cam axle assembly further comprises the set screw.
 6. The cam axle assembly of claim 1, wherein: the nut comprises a threaded aperture configured to receive a set screw, said set screw configured to prevent rotation of the nut relative to the cam axle when the cam axle assembly is installed on the archery bow; the threaded aperture is perpendicular to an axis along which the axle extends when the cam axle assembly is installed on the archery bow; the nut has an outer surface and an inner surface; the inner surface of the nut is configured to contact the limb end when the cam axle assembly is installed on the archery bow; the nut has an outer diameter at the inner surface that is greater than an outer diameter of the nut at the outer end, said outer diameters being measured perpendicular to an axis of the cam axle when the cam axle assembly is installed on the limb end of the archery bow; and the cam axle assembly further comprises the set screw.
 7. The cam axle assembly of claim 1, further comprising: a set screw configured to threadingly engage the nut and prevent rotation of the nut about the cam axle when the cam axle assembly is installed on the archery bow.
 8. The cam axle assembly of claim 1, further comprising: a set screw configured to threadingly engage the nut and prevent rotation of the nut about the cam axle when the cam axle assembly is installed on the archery bow, wherein a longitudinal axis of the set screw aligns with the axis of the cam axle when the cam axle assembly is installed on the archery bow and the set screw contacts an end of the cam axle to jam the nut and prevent rotation of the nut about the cam axle when the cam axle assembly is installed on the archery bow.
 9. The cam axle assembly of claim 1, wherein: the pair of limb ends are ends of two separate limbs.
 10. An archery bow comprising: a riser; a plurality of limbs extending generally rearward from the riser when the archery bow is assembled and in an upright position; a pair of cam axle assemblies, each cam axle assembly comprising: a cam axle having a threaded end, said cam axle configured to insert through a pair of limb ends of the plurality of limbs of the archery bow; and a nut configured to threadingly engage the threaded end of the cam axle to secure the cam axle to the pair of limb ends; a cam system mounted on the cam axle assembly, said cam system comprising at least one cam; and a bowstring supported by the cam of the cam system when installed on the archery bow.
 11. The archery bow of claim 10, wherein: the threaded end is a first threaded end of the cam axle; the nut is a first nut; the cam axle has a second end opposite the first end of the cam axle; the second end of the cam axle is threaded; and each cam axle assembly further comprises a second nut configured to threadingly engage the threaded second end of the cam axle to secure the cam axle to the pair of limb ends.
 12. The archery bow of claim 10, wherein: the at least one cam has a bearing assembly therein configured to receive the cam axle such that the cam axle supports the bearing and the cam.
 13. The archery bow of claim 10, wherein: the nut comprises a threaded aperture configured to receive a set screw, said set screw configured to prevent rotation of the nut relative to the cam axle when the cam axle assembly is installed on the archery bow; and each cam axle assembly further comprises the set screw.
 14. The archery bow of claim 10, wherein: the nut comprises a threaded aperture configured to receive a set screw, said set screw configured to prevent rotation of the nut relative to the cam axle when the cam axle assembly is installed on the archery bow; the threaded aperture is perpendicular to an axis along which the axle extends when the cam axle assembly is installed on the archery bow; and each cam axle assembly further comprises the set screw.
 15. The archery bow of claim 10, wherein: the nut comprises a threaded aperture configured to receive a set screw, said set screw configured to prevent rotation of the nut relative to the cam axle when the cam axle assembly is installed on the archery bow; the threaded aperture is perpendicular to an axis along which the axle extends when the cam axle assembly is installed on the archery bow; the nut has an outer surface and an inner surface; the inner surface of the nut is configured to contact the limb end when the cam axle assembly is installed on the archery bow; the nut has an outer diameter at the inner surface that is greater than an outer diameter of the nut at the outer end, said outer diameters being measured perpendicular to an axis of the cam axle when the cam axle assembly is installed on the limb end of the archery bow; and each cam axle assembly further comprises the set screw.
 16. The archery bow of claim 10, wherein: each cam axle assembly further comprises a set screw configured to threadingly engage the nut and prevent rotation of the nut about the cam axle when the cam axle assembly is installed on the archery bow.
 17. The archery bow of claim 10, wherein each cam axle assembly further comprises: a set screw configured to threadingly engage the nut and prevent rotation of the nut about the cam axle when the cam axle assembly is installed on the archery bow, wherein a longitudinal axis of the set screw aligns with the axis of the cam axle when the cam axle assembly is installed on the archery bow and the set screw contacts an end of the cam axle to jam the nut and prevent rotation of the nut about the cam axle when the cam axle assembly is assembled on the archery bow.
 18. The archery bow of claim 10, wherein: the pair of limb ends are ends of two separate limbs.
 19. The archery bow of claim 10 further comprising: a bow sight configured to mount to the riser when the archery bow is assembled.
 20. The archery bow of claim 10, wherein: the cam system comprises a pair of matched cams and the cam is one cam of the pair of matched cams. 